A weather radar system measures and maps rainfall intensity within a scanned area. Intense rainfall may include severe turbulence which can be hazardous to aircraft flight. The weather radar system includes an antenna receiver/transmitter unit. The unit emits a concentrated beam of microwave energy. The intensity of the rainfall at a given location is indicated by the color displayed. The rainfall data returned from the unit is displayed as color coded echos on a display.
The pilot relies on the radar tilt control to vertically examine the weather ahead of the aircraft. The pilot can typically tilt the radar beam plus or minus fifteen degrees. In an unstabilized radar, the tilt of the aircraft must be taken into account when computing the radar tilt. In a stabilized radar, the radar tilt is measured from a radar platform that is always parallel with the earth""s surface. The pilot modifies the tilt to determine the height of a storm. The computation is performed manually for each target knowing the tilt angle, the distance from the radar source and tilt of the aircraft. The algorithm for computing the relative altitude for the installed airborne radar system is typically published in the operator""s manual of the radar system.
The manual computation is subject to pilot error, resulting in the pilot flying the aircraft into unknown hazardous weather conditions.
A weather radar display system includes an altitude routine and a display. The altitude routine computes the altitude of a radar beam relative to altitude of an aircraft at a plurality of distance ranges away from the aircraft. The display, responsive to the altitude routine, shows weather features found by the radar beam and displays a textual indication of the computed relative altitude at each of the distance ranges. The displayed textual indication provides an estimated altitude for the displayed weather feature.
Each distance range is displayed as a range ring. Each of the textual indications is displayed at the corresponding range ring. The textual indication may be the relative altitude in thousands of feet. The textual indication indicates whether the relative altitude is positive or negative.
The display of the textual indication may be selectable by a user. The display may include a menu item for selecting the display of the textual indication.